The Ultra mobile broadband (UMB) technology is a new technology evolved from the CDMA 2000 access technology. Many technologies of the UWB air interface can substantially improve the performance of the CDMA 2000 access technology network and settle an essential base for providing more wireless multimedia service with higher-requirement to users.
In order to support the UMB air interface technology, related network is also under a new evolvement. FIG. 1 shows the network structure of the access network supporting the UMB technology in the art, wherein,
The access gateway (AGW) provides a “point of IP attachment” to the packet data network for access terminals (ATs). Thus, the AGW actually is the first-hop router for the AT.
An evolved base station (eBS) is a logic entity capable of communicating with an AT through a wireless carrier. For each AT being served, the eBS comprises an access network route instance (ANRI). For each AT, the eBS can play none or more of the following roles: forward link serving eBS (FLSE), reverse link serving eBS (RLSE), data attachment point (DAP).
The DAP is the bearer-plane point-of-contact for the AT to the AGW for forward-link data. The AGW sends the data and signaling related to the AT to the DAP. The reverse link data from the AT can either be transmitted to the AGW via the DAP or directly transmitted to the AGW by the RLSE.
The DAP can be relocated to a different eBS during the lifetime of the packet data session based on several factors, such as performance considerations. An example may be to move the DAP when the eBS hosting the DAP is no longer a Route Set member.
A session reference network controller (SRNC) is responsible for maintaining the session reference with the AT. The SRNC is also responsible for supporting idle state management of the AT, and providing paging control functions when the AT is idle.
It is noted that the SRNC can be located in various ways, such as being a standalone entity, or being collocated in an eBS or in an AGW. If the SRNC is collocated into the eBS, both of them can share one ANRI.
In the network structure as shown in FIG. 1, reference point U1 is used to carry the control and bearer information between the eBS and the AGW; reference point U2 is used to carry the control information between the SRNC and the eBS; reference point U3 is used to carry the control and bearer information between two eBSs; reference point U4 is used to carry the control information between SRNCs; and reference point U6 is used to carry the control information between the SRNC and the AGW.
At the same time, accounting function is a basic function required by a wireless communication network, and this function is also required by the access network supporting the UMB. The accounting principle of the UMB network is that the eBS/DAP sends the accounting information of wireless resources to the AGW, and the AGW forwards the information to the Authentication Authorization Accounting (AAA) unit of the core network so as to generate uniform user accounting records for users.
Current access network technology already contains accounting function in some aspects, for example, when a UMB session is established or when an eBS is removed from the route set of a certain AT, the eBS/DAP all sends the related accounting information to the AGW. However, some aspects are ignored in the art. That is to say, there is no accounting information interaction in the following processes or application.
As shown in FIG. 2, there is no accounting function for the current UMB session release process initiated by an AT or SRNC. As shown in FIG. 2, the current UMB session release process initiated by an AT or SRNC comprises the following steps:
S202, an AT or the ANRI of the AT initiates a UMB session releasing, wherein it is assumed that the ANRI is the SRNC. After releasing the UMB session, the SRNC sends Inter-ANSI signaling (IAS)—the session release message to all ANRIs and DAP of the route set. The following Steps S204-S206 and S208-S210 can be performed synchronously.
S204, the SRNC sends the IAS-Session Release message to the eBS1/FLSE/RLSE, and starts a timer Tsr-ias at the same time. The message indicates that the SRNC has released the current UMB session, and the eBS1/FLSE/RLSE should deallocate the resources assigned to the AT and purge the UMB session in the eBS1/FLSE/RLSE.
S206, upon receipt of the IAS-Session Release message, the eBS1/FLSE/RLSE sends an IAS-Session Release Ack message to the SRNC. The SRNC stops the timer Tsr-ias.
S208, the SRNC sends the IAS-Session Release message to the DAP and starts a timer Tsr-ias at the same time. The message indicates that the SRNC has released the current UMB session, thus the DAP must release the resources allocated to the AT, eliminate the UMB session of the AT from the DAP, and release the Proxy Mobile IP (PMIP) tunnel between the AGW and DAP.
S210, after receiving the IAS-Session Release message, the DAP sends an IAS-Session Release Ack message to the SRNC which stops timer the Tsr-ias.
S212, after receiving the IAS-Session Release message from the SRNC, the DAP sends a PMIP-Registration Request message to the AGW with a Lifetime timer value of zero to release the PMIP tunnel between the AGW and DAP for the AT. The DAP starts a timer Trrq-pmip.
S214, after receiving the PMIP-Registration Request message from the DAP, the AGW releases tunnel and sends a PMIP-Registration Reply message to the DAP. The DAP stops the timer Trrq-pmip.
As shown in FIG. 3, the current UMB session release process, caused by the UMB packet data session release initiated by the AGW, has also no accounting function. It comprises the following steps:
S302, the AGW sends a PMIP-Registration Revocation message to the DAP and starts a timer Trrv.
S304, after receiving the PMIP-Registration Revocation message, the DAP sends a PMIP-Revocation Acknowledge message to the AGW. The AGW stops the timer Trrv.
S306, it is assumed that the DAP is not in the route set. The DAP sends an IAS-packet data session release message to the SRNC and starts a timer Tpdsr-ias. The IAS-packet data release message is used to indicate that the packet data session has been released.
S308, after receiving the IAS-packet data session release message, the SRNC sends an IAS-packet data release response message to the DAP. The DAP stops the timer Tpdsr-ias.
S310, after receiving the IAS-packet data session release message, the SRNC initiates the release of the UMB session. The SRNC shall send the IAS-session release message to all ANRIs in the route set and DAP.
S312, the SRNC sends the IAS-session release message to the eBS1/FLSE/RLSE and starts a timer Tsr-ias. The message indicates that the SRNC has released the current UMB session and the eBS1/FLSE/RLSE should release the resources allocated to the AT and eliminate the UMB session of the AT from the eBS1/FLSE/RLSE.
S314, after receiving the IAS-Session Release message, the eBS1/FLSE/RLSE sends an IAS-Session Release Ack message to the SRNC. The SRNC stops the timer Tsr-ias.
Based on the above description, above-mentioned flows do not transfer related accounting information to the AGW. In addition, there is the case in which the active access terminal has multiple proxy mobile IP tunnels, and no solution is provided in the art to solve the accounting process upon releasing multiple proxy mobile IP tunnels. Thus, these flows are short of function supporting accounting, which is a severe limitation to the real network and brings substantial impairment to the benefits of operators.